I would just like to say I've played and loved every assassins creed to date, and I must say I'm bitterly disappointed by this game..
I thoroughly enjoyed the first 2 hours and would leave a hugely positive review, however now I've past the point of being wow'd by the beautiful scenery I've found more glitches, problems and general irritating niggles than I can cope with...
I have no idea what they have done to the free running/climbing but it's a step backwards, you find yourself climbing on the wrong things and randomly not grabbing things you should be able to, the controls are clunky and completely unrefined. The horse control is a joke and would make no difference if they had just left them out.
The fighting is infuriating, 6 out of 10 air assassinations glitch and you end up landing on the floor being stabbed by the guy you ment to kill by his musket. The general combat has a few new fancy moves but definitely should have kept the original combat system and incorporated these new combos with that. (And to those who have already played this game will know what I mean when I say there is a complete lack of combat dialog as you will hear in the most annoying voice repeatably saying 'so slow' virtually every time you enter combat)
There are some really good ideas and concepts in this game which is its saving grace in my opinion such as when you have acquired your ship, the sea battles are really entertaining and a welcome breath of fresh air, and having your own little village is cool too, but these are overcast by the nicks and niggles which are generally more important.
I've tried to be as honest as I can in this review but please do yourself a favour and rent the game first and make up your own mind about it. I would have been taking this back for a refund if I had paid 40 pound for it!